The laser is a delicate machine with several consumable parts. In order to maintain the laser, Freeside asks for a $5/hour usage fee from members using the laser. These funds will be used to repair the laser, replace tubes, lenses, or other items that wear out, and when there is a surplus, make upgrades.

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The laser is a delicate machine with several consumable parts. In order to maintain the laser, Freeside asks for a $5/hour usage fee from members using the laser. These funds will be used to repair the laser, replace tubes, lenses, or other items that wear out, and when there is a surplus, make upgrades.

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Laser usage fees should be paid to the treasurer with any of methods of payment accepted for dues. Please indicate that the payment is for laser usage for proper accounting.

== Restrictions ==

== Restrictions ==

Revision as of 00:05, 9 July 2014

Contents

Zone

Owner(s)

Freeside

Permissions

For general use by members after they have completed an appropriate training course. Treat this equipment as if it were your own cleaning items off of the top of the machine and around its table after usage.

Usage Fee

The laser is a delicate machine with several consumable parts. In order to maintain the laser, Freeside asks for a $5/hour usage fee from members using the laser. These funds will be used to repair the laser, replace tubes, lenses, or other items that wear out, and when there is a surplus, make upgrades.

Laser usage fees should be paid to the treasurer with any of methods of payment accepted for dues. Please indicate that the payment is for laser usage for proper accounting.

Restrictions

The laser cutter is a CNC(Computer Numeric Control) machine capable of the following (See the Laser Library for more details):

Cutting

* paper
* cardboard
* plastics up to 1/2" depending on type
* craft foam
* plywood of certain thicknesses depending on number of layers as well as what type of bonding glue was used
* other stuff I haven't yet tried

Engraving (raster and vector)

* cardboard
* plastic
* wood
* glass
* dark stone
* ceramic
* leather

Caution

Contrary to popular belief lasers don't melt things. They remove material via a process called sublimation; turning an object from the solid state directly to the gaseous state skipping the liquid stage almost completely.

The laser uses an RF excited CO2 gas laser producing an invisible to the human eye beam at 1090um. Almost everything is opaque to this wavelength and as such if it can sublimate the material it will. This means that if you put *anything* in the path of the laser it'll try to cut it. If it can't cut the material and it doesn't reflect the beam it *WILL* heat it up very very rapidly. The excited gas you can visually see in the tube is kind of the same thing you see in neon signs. 25KV is applied and the gas is excited to the point where it has to release extra electrons and you see this as light. Do not forget that the beam coming out of the tube is completely invisible and completely dangerous.

Do not, under any circumstance, power the laser cutter on unless:

the E-stop on the machine is on

the machine controller is attached

the operating system is completely booted

Mach3 is running and in the foreground

the E-stop in Mach3 is engaged

Specifications

In this picture from left to right you can see:

24VDC power supply; large aluminum case

12VDC power supply; small aluminum case

In the back are 3 Keling stepper drivers; black aluminum cases with green wiring terminals

In front of those are 2 120VAC solid state relays (not wired and currently not present in the enclosure); grey plastic cases

Breakout board

Power entry

Hole for 120VAC duplex outlet

In the second picture you can see the high voltage power supply

The gantry is driven by a single dual-shaft stepper motor. This motor has a driveshaft on either side that goes to a bearing mechanism attached to the Y rails. Nearest this bearing mechanism there is a timing belt pulley on the shaft. The belt rides on this pulley and connects to the gantry's carriage to pull it back and forth. All motion in the laser cutter is established via pulling as you can't push a belt.

The lens carriage is driven by a stepper motor with a timing belt attached to the carriage.

The wiring exists for a Z(table) stepper but it's not currently installed. The large timing gear can be turned by hand to adjust the table up/down.

The laser cutter is supported by several pieces of equipment outside of its own enclosure:
From left to right

The coolant tank stores an amount of water/antifreeze mixture as well as houses the 24V bilge pump to circulate the coolant. Because of the amount of coolant available the temperature increase is not noticeable.

The air assist pump pumps air into the nozzle attached to the focusing lens on the laser carriage. It's purpose is twofold: keep smoke/debris from out of the line of the laser's beam and off of the optics themselves, and assist the sublimation process by expelling the gasses created

The fume extractor draws air in from the front of the laser cutter enclosure, across the cutting surface, and out through the back of the enclosure. (Actual equipment subject to change)

The laser beam itself is guided to the cutting nozzle using a "flying optic" system. This means that the laser tube stays in one place and the beam is directed around the enclosure using mirrors. The beam exits the laser tube and hits the first mirror at a ~45 degree angle. It then is reflected onto the gantry's mirror again hitting at ~45 degree angle. It is then reflected onto the carriage mirror at ~45 degree angle and then hits the focusing lens.

Tips

Test power level and feedrate on a piece of material like the one you intend to use.

More isn't always better in regard to power.

More isn't always better in regard to assist air.

When watching the laser cut/engrave wood, wear sunglasses, cutting goggles, or a welding helmet. The light coming off of the material is extremely bright.

Never look directly at the item being cut without at least one material between you and the beam ie: no peeking in the vent holes without protective glasses

From time to time the gantry gets out of square due to slop in the belts and loosening screws. In order to fix this you need to: